Who is willing to train tomorrow’s American workers?

FORTUNE — Baroness Shriti Vadera, a former U.K. cabinet office minister, delivered some sober news on Wednesday: The United States is one of two or three countries where older people have higher level skills than younger people.

And there was more: “We might be the only generation to not bequeath a better life to the next one,” she said.

Speaking at Fortune’s Most Powerful Women Summit in Washington, D.C., Vadera, who was an economic adviser to former U.K. Prime Minister Gordon Brown, hit on the issue of the skills gap — the mismatch between what background and expertise employers need from employees and the skills that job candidates possess.

The skills gap is considered a hurdle in the U.S.’s efforts to fully recover from its most recent recession. The Bureau of Labor Statistics has reported that despite the fact that 12 million Americans are currently looking for work, U.S. companies have nearly 4 million open jobs. Last year, for instance, Microsoft MSFT announced that it was having trouble filling its 6,000 open positions because it couldn’t find job candidates in the U.S. with adequate qualifications.

According to Vadera, the skills gap spells trouble America’s future ability to compete in the global market. It’s also bad news for the country’s long-term prosperity since people not “living up to their potential’ permanently puts “a depression on the economy,” she said.

Vadera shared the stage at the summit with Joyce Russell, president of Adecco Staffing U.S., who advocated for companies’ use of flexible workers, the kind who are employed by staffing firms like Adecco, which loans workers to its client companies. Russell argued that such arrangements allow companies and workers to try each other on for size and often lead to full-time employment.

Vadera argued that the use of such flexible workers contributes to the growing skills gap. If a company employs temporary workers, it’s not going to put resources towards advancing their skills. “Why would you invest in [employees’] skills if they’re just going to leave?” she asked.

Corporations’ investment in worker skills is crucial, Vadera said, since “you can’t expect the public sector” to address workforce training needs on its own.